抄録
Against the backdrop of accelerating climate change and human activity, identifying ecological thresholds—critical tipping points for state shifts and functional degradation—has become a frontier in physical geography and ecology. This study systematically reviews the theoretical frameworks, methodologies, and controlling mechanisms of dryland ecosystem thresholds. It first standardizes threshold identification logic, emphasizing the spatial heterogeneity inherent in coupled climate-geomorphology-vegetation-soil systems. Next, it synthesizes advancements in remote sensing, GIS analysis, long-term observation, and numerical modeling, highlighting the necessity of multi-source, multi-scale data integration. By analyzing nonlinear feedbacks driven by climate variability, extreme events, and human disturbance, this study reveals both regional and global patterns in threshold evolution. Finally, it addresses key challenges, including the cumulative effects of compound stresses, cross-scale process coupling, and uncertainty quantification. As crossing these thresholds often leads to irreversible land degradation, this physical geography-based framework provides essential insights for improving predictability and risk assessment, ultimately supporting climate adaptation and the UN Sustainable Development Goals in drylands.
